Control for roll stabilizing and energy consumption of Autonomous Underwater Vehicle near water surface

Considering the case of AUV (Autonomous Underwater Vehicle) navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to improve roll stabilizing performance of AUV. Control system design is based on GPC (General Predictive Control) theory. Coupling horizontal motion model of AUV is equivalently transformed into a discrete difference equation of roll. Then, the difference equation is regarded as predictive model of GPC. GPC algorithm of AUV roll motion is derived with performance index based on roll stabilizing performance and energy consumption used for roll control. Roll angular velocity is introduced into GPC performance index for reducing the overshoot and fluctuation due to fast varying of roll angle. In allusion to time-variant parameters in roll motion model, recursive least square method is adopted for parameter estimation. Simulation results show better AUV roll stabilizing performance and minimized energy consumption used for roll control.